Process of making reinforced gas flasks



C. H. LINDSAY PROQESS OF MAKING REINFORCED GAS FLASKS April 3, 1945.

Filed March 3, 1943 E E: =5:E

Patented Apr. 3, 1945 UNITED STATES PATENT OFFICE 2,373,038 PROCESS OFMAKING REINFORCED GAS FLASKS Charles H. Lindsay, Elmira, N. Y. assignorto American-La France-Foamite Corporation, Elmira, N. Y., a corporationof New York Application March 3, 1943, Serial No. 477,899 1 Claim. (Cl.fill- 14832) The invention relates to containers or flasks By thepresent invention the wrapping process for holding gases under pressure,such as liquid is so simplified and shortened that the job can oxygen,etc., and includes a new method of be completed in about one-half of theleast time applying wire wrappings to such flasks to increase heretoforerequired, and on a regular quantity their strength and render them proofagainst production basis, and without sacrificeof any adfragmentation itstruck by missiles in war-rare, vantage; in fact, it is done with somesaving of also the flasks so made. material since the applied flangesare not used.

It is already known to reinforce gun barrels, The new processisillustrated diagrammatically gas flasks and the like in this manner.The in accompanying drawing, Fig. 1 showing the usual operation is towind the wire on the flask lo flask wrapped and the ends of the wireanchored. by rotating it like a spool. or bobbin, laying the ready to beprepared for dipping. Fig. 2 illussuccesslve spires close .together orin contact and trates the completed flask, and Fig. 3 a fragthereaftercovering the wrapping with a coating mentary, greatly enlarged scalesection of a of metal, which is done by dipping the wrapped wrapped andcoated flask.

- flask in a molten bath of tin .or other suitable According to thisinvention, instead of passing metal or alloy. The coating locks thespires on the beginning end of the wire through a hole the flask makinga container of great strength in an applied flange, when starting thewinding,

in proportion to its weight. The wire is of high I clamp such enddirectly in the chuck I of the tensile strength, sometimes called musicwire, winding machine, by which the flask is gripped to and is dimcultto handle on account or its stiff be rotated. This makes the chuck atemporary sprlnginess on which account the process of makanchorage forstarting the winding. By the acing a neat wrapping with neatly finishedtermition of the machine which rotates the chuck and nations is dimcultand time-consuming. flask, the wire is then wound quickly over the Thepractice is to alflx two circumferential neck part or the flask asindicated at 2, conflanged rings to the cylindrical flask body beforetinued on over the cylindrical body of the flask starting the winding,one near each end. These in the usual way and, as indicated, down to theare to serve as the limiting boundaries for the opposite end where thewrapping is to terminate, wrapping and as anchorages for the two ends ofusually at the base of the cylindrical part. the wire, to hold themuntil the flask canbe Then, with the machine stopped and, while dipped.They are usually made as split rings of still retaining the windingtension in the wire. L-shaped section and appropriately attached to theterminal spires of the winding at each end the chucks of the windingmachine to retain the are fastened or anchored to the flask by brazingpositions on the flask to which they have been slew of them together, asindicated at the points set. The winding is started by passing thebegin- 4 and I, and by means of a brazing or soldering fining end of thewire through a hole in one of alloy specially selected for the purpose.

the flanges and then rotating the flask so as to The special feature ofthis alloy is its fusion wind on the wire up to the flange of the ringpoint, which is enough below the critical temperat the other end. Whenthis is done and while ature of the alloy steel of which the flask wallwi s still e d u er its strong winding is made that it can be used tomake the wire tension the flanges are turned down over and 40 junctionwithout imparting a temperature to the upon the adjacent spires of thewire so as to clamp steel wall which exceeds or dangerously apit againstuncoiling or slipping. Aloosely wound preaches that temperature.Different steels wrappingis not an effective reinforcement. The havediflerent critical temperatures but all of wire ends are then trimmedoil and the flanges those used for flask manufacture are unaffected wilwn W the pires to make a neat job, by locally applied temperatures lowerthan 1250" whereupon the flaskis dipped in the molten bath ll". At thesame time the fusion point of the to complete the operation. The flangesserve no brazing compound is sufllclently above the purpose, except todetermine the beginning and temperature at which the bath of dippingmetal end of t w ing and prevent un iling until is maintained, that oncethe junction or anchorthe dip-coat can be applied, and althou h afte ageof the terminal spires has been accomplished. d ppin h y b ome ntegralparts of the flask such junction will not be thereafter impaired orcoverlnaheing or soft metal or brass. they add weakened when the wrappedflask is dipped. The little to its tensile strength. They are in factbath temperature need not exceed, say about 600 A subject to iniuryresulting in a loose wire Eat which point tin and its alloys aresulflciently fluid for effective coating results. Suitable braz- 2aavaoaa ing compounds. including in this term hard or flask with asecond mersely-woimd layer on:- silver solders. are available on themarket. lying the first, in the same manner, this is n01 A strip 01'such a compound iusible within the necessary ii a single wireorappropriate diametel range indicated, say at 1171i 11"., is slippedunder is tightly wound and securely anchored prior to or laid on top ora few or the terminal spires dipping. at each point 4 and I, and thenmelted by the riskoi' wire-slipping duringtheooating operation.localized application of heat, as by a handand equally important. duringthe handling ol torch, an electric are or more conveniently. the theflask while being transported from the windtongs of an induction heater,thus permanently ing department to the dippin department. A!- anchoringthe two ends or the wrapping wire in tor dip ing. the risk or slippingis or course over. position. The heat applied for this purpose is Iclaim: momentary, and even though it might involve The process ofproducing wire-wrapped flasks a temperature somewhat above the indicatedh a iti a s e which omprises setting fusion range, is always sai'elybelowvthat which the flask between chucks in a winding machine mightalter the crystal structure or the alloy steel whereby it can be rotatedon its longitudinal or the flask to afl'ect its strength. axis,fastening the end or the wire to the machine The next steps involve therelease or the tension so as to lay the wire against the surface of theon the lead 6 of the winding wire and the cutting flask in the positionof the initial spire or the on or the wire ends close to each anchoragewinding to be wound thereon, rotating the flask point, 4 and ;I, andfinally the dipping oi. the to wind the wire around the samev undertension flask in the molten bath of tin or other coating and so as toenvelope the flask with the winding. metal. anchoring the initial spiresoi the wire to the The flask then appears as indicated in Fig. 2 flaskwall by brazing a few of them together by with the wrapping wire 3completely coated, and means of a brazing alloy having a fusion pointeach cut end of the wire covered over and conwell below the criticaltemperature of the flask cealed in the metal coat. This is indicated,steel and using the brazing heat so momentarily lng usually in the orderof .034 inch. Since the some of the last wound spires oi the wire to thepp ng thus made has no spun-over flan es at flask wall in the samemanner as above preits ends the overall flask diameter has not beenscribed tor the initial spires, cutting 08 the free increased by thewinding process greater than ends 01' the wire beyond the brazed spotsand then the thickness or the wire and its thin tin coat dipping andcoating the wound flask in a molten l, and the flask is thereforevirtually unchanged I metallic bath while maintaining such bath at afrom its original dimension. temperature lower than the fusion point orsaid While it is, of course, apparent that the windbrazing alloy. ingcould, if desired, be continued to cover the CHARLES H. LINDSAY.

